How big are the coin pieces? (Like Gold Pieces and stuff)

[Sims]

Are they 2 inches? And does the material change the size? (I can see a Platnium coin being bigger than a Gold piece)

I'm just curious for when I break the game.

[Veyr]

I believe all coins are 50 to the pound.

[Yora]

Which actually makes gold coins the smallest ones.

[Firechanter]

You find the actual size in the PHB in the Adventuring chapter, can't give you the exact page tho. They seem to be 3cm in diameter, that's about 6/5 inch. _Unless_ my (localized) version of the PHB has printed the coin image in a different scale!
As far as I know, all coins are the same diameter, and accordingly have different thickness depending on the material density.

We also know there are 50GP to a pound, so 1GP weighs about 9g. The density of gold is about 19g/cm³ (pure gold actually, while coins are typically of alloys with silver or copper to make them harder, but w/e).

Thus we can calulate their thickness:
the surface area of a coin face is 1,5^2*3,14 cm², or 7 cm².
We know that the volume of a GP must be 9/19 = 0,47cm³
Thus the thickness is 0,47 / 7 = 0,068cm ~ 0,7mm = 1/36" = _very thin_.

Platinum is even denser (21.45) so a coin of the same size will even be a bit thinner.
Silver only has a density of 10.5 so it will be almost twice as thick as the gold coin.

[Veyr]

For reference, an American dime would be about twice the thickness of the gold coin that Firechanter just calculated.

[Kosjsjach]

It also makes mithral coins (relatively) huge. Items made out of mithral weigh half as much as their iron counterparts, which infers that it has half it's density. Gold is roughly 2.5 times denser than iron, so a standard coin (50/lb) of mithral is approximately 5 times as large as it's gold counterpart.

EDIT: But then, as pointed out above, an actual 50/lb gold coin is rather puny.

[Firechanter]

Here we have it, Mithral is Titanium. ^^

[aart lover]

an actual size picture of one is in the 3.5 players handbook, it's about 2 inches in diameter.

[Yora]

That'd be 5 cm. I'm going to look it up now, but I'm sure that's wrong.

When I even care to count the amount of prescious metal carried by the PCs, I don't count indivdual coins but rather say "they have gold coins of varying shapes and sizes worth the abitrary value of x gp". And the ammount of gold worth 50 gp weighs 1 pound. Though its not actually 50 coins, but possible more or less, depending on the material.
Basically, coin is worth it's material value, the shape a piece of metal comes in is irrelevant.

[Kosjsjach]

Here we have it, Mithral is Titanium. ^^
That's... actually really really cool.

[aart lover]

That'd be 5 cm. I'm going to look it up now, but I'm sure that's wrong.

When I even care to count the amount of prescious metal carried by the PCs, I don't count indivdual coins but rather say "they have gold coins of varying shapes and sizes worth the abitrary value of x gp". And the ammount of gold worth 50 gp weighs 1 pound. Though its not actually 50 coins, but possible more or less, depending on the material.
Basically, coin is worth it's material value, the shape a piece of metal comes in is irrelevant.

*measures picture*. oh, whatever:smallannoyed:, i've never been good at estimating length anyways:smalltongue:

[Yora]

1/50 of a pound is 9.1g.

The 2€ coin weighs 8.5g and is the biggest euro coin.
At 1145.69 mm^3 or 1.14569 cm^3, its mass is 7.42 g/cm^3. So slice this one into three parts and you about have your average gold coin for that size. :smallbiggrin:

Silver has a density of 10.5, so it would be just a slightly flatter than the 2€ coin at the same diameter.
Coper has a density of 8.9, so it would be ecen closer to that size.

[Goober4473]

I would assume a gold piece wouldn't be solid gold. It would probably have enough other, lighter metals to bring it up to size with the others.

[Gnoman]

That doesn't work in a specie economy. Merchants have to be able to weigh the coin in order to ensure that the proper amount of money is being paid. Modern Fiat systems lack this problem, so coining base metals works.

[Darth Stabber]

I use realworld (american) coins as a basis. Coppers are pennies. Silvers and Gold are nickles. Plats are quarters. the 1000gp coin I am about to add will be half-dollars.

[Moriato]

It also makes mithral coins (relatively) huge. Items made out of mithral weigh half as much as their iron counterparts, which infers that it has half it's density. Gold is roughly 2.5 times denser than iron, so a standard coin (50/lb) of mithral is approximately 5 times as large as it's gold counterpart.


Who uses mithral as a currency? I've never run accross mithral pieces, maybe that's why.

[ffone]

Interestingly, platinum and mithral have the same price per pound in DnD. Mithral 'other items' are +500 gp / lb (assuming whatever material is replaced its negligible), and platinum coins are 50 / lb for 500 gp / lb value as well.

Since mithral is lighter, a pound would be bigger. This could explain why it wouldn't commonly be used as currency: might as well use platinum instead. That and it's too valuable - better used for armor, whereas plat/gold/silver serve very little practical purpose beyond just being agreed-on currencies.

[TheOOB]

You find the actual size in the PHB in the Adventuring chapter, can't give you the exact page tho. They seem to be 3cm in diameter, that's about 6/5 inch. _Unless_ my (localized) version of the PHB has printed the coin image in a different scale!
As far as I know, all coins are the same diameter, and accordingly have different thickness depending on the material density.

We also know there are 50GP to a pound, so 1GP weighs about 9g. The density of gold is about 19g/cm³ (pure gold actually, while coins are typically of alloys with silver or copper to make them harder, but w/e).

Thus we can calulate their thickness:
the surface area of a coin face is 1,5^2*3,14 cm², or 7 cm².
We know that the volume of a GP must be 9/19 = 0,47cm³
Thus the thickness is 0,47 / 7 = 0,068cm ~ 0,7mm = 1/36" = _very thin_.

Platinum is even denser (21.45) so a coin of the same size will even be a bit thinner.
Silver only has a density of 10.5 so it will be almost twice as thick as the gold coin.

When someone uses real world science and logic in a discussion about fantasy worlds, Pelor kills a cat girl. Coins are about 2 inches across because they should look big and important. They weigh 1/50th of a pound because it's an easy number and the designers didn't want money weight to matter unless there is a lot of it. Please thing of the cat girls.

[Lyndworm]

Frank and K also did some calculations on the subject, although theirs was more opinionated and less mathy.


From the standpoint of the adventurer, the primary difficulty of the D&D currency system is that the lack of a coherent banking and paper currency system means that there are profound limits to what you could possibly purchase even with platinum. But the currency system hurts on the other end as well. Untrained labor gets a silverpiece a week. That’s 500 copper coins a year, which means that no matter how cheap things are they can only make one purchase a day most of the time. That’s pretty stifling to the economy, in that however much gets produced, no one can buy it. Demand, from the economics standpoint, is strangled to the point where large production outputs don’t even matter (remember that in economics Demand doesn’t mean “what people want”, it means “what people are willing and able to pay for”, so if the average person only has 500 discreet pieces of currency per year, that puts an absolute cap on economic demand, even though the people are of course both needy and greedy enough to want anything you happen to produce).

What’s worse, those coins are heavy. For our next demonstration, reach into your change drawer and fish out nine pennies. That’s a decent lump in your pocket, neh? That’s about one copper piece. Gold pieces are smaller (less than half the size, actually), but weigh the same. D&D currency, therefore, is more like a Monopoly playing piece than it is like a modern or ancient coin. There’s no reason to even believe these things are round, people are seriously marching around gold hats and silver dogs as the basic medium of exchange.

Now, you may ask yourself why these coins are so titanic compared to real coins. The answer is because having piles of coins is awesome. Dragons are supposed to sleep on that stuff, and that requires big piles of coins. Consider my own mattress, which is a “twin-size” (pretty reasonable for a single medium-size creature) and nearly .2 cubic meters. If it was made out of gold, it would be about 3.9 tonnes. That’s about eighty-six hundred pounds, and even with the ginormous coins in D&D, that’s four hundred and thirty thousand gold pieces. In previous editions, that sort of thing was simply accepted and very powerful dragons really did have the millions of gold pieces – which was actually fine. Since third edition, they’ve been trying to make gold actually equal character power, and the result has been that dragon hoards are. . . really small. None of this “We need to get a wagon team to haul it all away”, no. In 3rd edition, hoard sizes have become manageable, even ridiculously tiny. When a 6th level party defeats a powerful and wealthy monster, they can expect to find. . . nearly a liter of gold. That is, the treasure “hoard” of that evil dragon you defeated will actually fit into an Evian bottle.

There are two ways to handle this:


Live with the fact that treasures are small and unexciting in modern D&D.
Live with the fact that characters who grab a realistic dragon’s hoard become filthy stinking rich and this fundamentally changes the way they interact with society.

But once you accept that the realities of the wish based economy, you actually don’t have to live with characters unbalancing the game once they find a real mattress filled with gold. That’s not even a problem once characters are no longer excited by a +2 enhancement bonus to a stat or a +3 enhancement bonus to Armor. Which means somewhere between 9th and 13th level it’s perfectly fine for players to find actual money without unbalancing the game. Really, you can stop worrying about it.

[Firechanter]

When someone uses real world science and logic in a discussion about fantasy worlds, Pelor kills a cat girl.

1. Good! Death to all cat-girls!
2. What's your problem with calculating the thickness of a coin?


Coins are about 2 inches across because they should look big and important.

Only they aren't. Neither are they 2 inches across, but 6/5", as the PHB _explicitly_ shows, nor are they important. A gold coin is nearly worthless compared to actual history. According to DMG, a "simple" lifestyle (or whatever it was called) costs almost a pound of gold per _month_.
They are pretty big compared to historical gold coins, but still not quite as big as you seem to believe.


Since third edition, they’ve been trying to make gold actually equal character power, and the result has been that dragon hoards are. . . really small.

When I talked to my fellow players about our next D&D game, one said he isn't comfortable with having to hoard treasure to buy gear. I said fine, how about we separate ingame wealth and metagame resources. Will have to work out the details, but the cornerstones are:
1) keep using the WBL table, but define GP as "Gear Points" rather than "Gold Pieces".
2) you can't buy or upgrade magical items with gold. However, you can expend Gear Points to do so. Looted magical items count against your Gear Points, but you can trade them in.
3) Any actual gold you find is there to blow on mundane comforts, or "ale and whores".

[Peregrine]

You find the actual size in the PHB in the Adventuring chapter, can't give you the exact page tho. They seem to be 3cm in diameter, that's about 6/5 inch. _Unless_ my (localized) version of the PHB has printed the coin image in a different scale!

The last page of that chapter, in fact; p.168 in my (standard, English) PHB, which also shows them being 3cm across.

On the subject of science and catgirls: This isn't an antimatter nuke we're talking about here. The only "science" this is trying to introduce is the density of metals. There are three possible ways of working this out: D&D metals have the same densities as in the real world. Catgirls may or may not suffer, depending on how much you consider this to be "an unwelcome intrusion of science". It's more likely "unwelcome" if what we know for sure about D&D coins doesn't agree with real-world values. D&D metals have different densities, whatever works most conveniently for your maths. This is what's known in technical terms as "pulling it out of your donkey's saddlebag", or something like that. But this may be the only way to make the explicit D&D rules fit. D&D metals all have the same density, so all coins are the same size, since there's fifty to the pound. This is harmless to catgirls but harmful to suspension of disbelief. It's also a subset of the previous point, but chosen for maximum simplicity.
The picture in question only says that a gold piece is that size. I'm going to make some fairly arbitrary assumptions now, and see what figures come out.

As Gnoman points out, the weights and purities of the precious metals need to be standardised (or readily ascertained) for coins to be useful. Let's say gold coins are 18ct (25% copper), since pure gold is pretty darn soft. Using figures for each metals' room temperature density from Wikipedia, I calculate a density of 16.7 g/cm³. The diameter of the gold coin in the PHB is 3 cm; at 50 coins to a pound, its volume is 0.543 cm³. Thus, a perfectly cylindrical coin is 0.768mm thick.

That sounds pretty flimsy, even if we consider that this is for a perfectly cylindrical coin; one with more rounded edges and/or an engraved design would be slightly thicker at its maximum. Fortunately, decreasing the diameter a little will increase the thickness by quite a bit. If we go for a nominal thickness of 1.5mm (almost twice as thick), the diameter becomes a still-workable 2.14cm. It's perhaps more of a "gold penny" now, but I'm happy with it. (A purer gold coin would be even smaller.)

Now, for the other denominations, we're keeping the "fifty to a pound" rule, and aiming for similar thicknesses, but the diameter is the big variable.

Let's just use the density of pure copper, 8.94 g/cm³ (even ancient real-world cultures could smelt copper to over 99% purity). That's pretty close to half the density of our 18ct gold coins; a copper coin's volume is 1.01 cm³. At the same thickness, 1.5mm, our copper coins are just slightly smaller than the book's idea of a gold coin, at 2.93cm in diameter.

I can't seem to find any information on the purity of silver extracted by historical methods like the patio process (an almost alchemical method that would be perfectly plausible in a typical D&D fantasy world). Let's stick with the pure-metal density, 10.5 g/cm³. The coin has a volume of 0.864 cm³, and with a thickness of 1.5mm again, its diameter is 2.71cm, which as we'd expect is in between the copper and gold coins.

Platinum has little history of refining, and I can't find any purity figures for it either. It's denser than gold, twice as dense as silver, at 21.45 g/cm³. Pure, and still at 1.5mm thick, it would make little pennies just 1.90cm across. But pure platinum is not very workable; let's assume that "platinum" pieces are a standardised white gold, let's say 12:6:6 gold/platinum/copper (this may be my most arbitrary decision yet). This has a density of around 17.2 g/cm³. Such coins will be just slightly smaller than gold ones, at 2.11cm across.

Electrum coins, being gold and silver, would be between 2.14cm (or less, for purer gold) and 2.71cm across, depending on proportions.

In short, D&D coins are plausible, at real-world densities, if they're two to three centimetres in diameter (one inch, give or take a sixth).

[Draz74]

For reference, an American dime would be about twice the thickness of the gold coin that Firechanter just calculated.

And, since gold is ridiculously soft (soft enough to mold a little bit with your hands, if it's pure; still amazingly soft as an alloy), these super-thin gold coins flop around like paper and might be damaged if you sneeze on them. :smallamused:

[Veyr]

That doesn't work in a specie economy. Merchants have to be able to weigh the coin in order to ensure that the proper amount of money is being paid. Modern Fiat systems lack this problem, so coining base metals works.
Sure it can. You just need a known, standardized alloy. For example, the British pound sterling? "Sterling silver" is, by definition, 92.5% silver (by weight) and the rest is other metals, usually copper.


And, since gold is ridiculously soft (soft enough to mold a little bit with your hands, if it's pure; still amazingly soft as an alloy), these super-thin gold coins flop around like paper and might be damaged if you sneeze on them. :smallamused:
Very, very true; that thought had crossed my mind when I wrote it.

[Gnoman]

Sure it can. You just need a known, standardized alloy. For example, the British pound sterling? "Sterling silver" is, by definition, 92.5% silver (by weight) and the rest is other metals, usually copper.


That works only if the coin came from a mint that is both trustworth enough to cheat and powerful enough to punish misuse of it's image. In the assumed setting of DND, this situation does not exist. (Interestingly, there's no spell that I know of the determine the purity of a metal, which would make baser alloys feasible.)

[Veyr]

That works only if the coin came from a mint that is both trustworth enough to cheat and powerful enough to punish misuse of it's image. In the assumed setting of DND, this situation does not exist. (Interestingly, there's no spell that I know of the determine the purity of a metal, which would make baser alloys feasible.)
Fair enough.

I'll bet something like that spell exists somewhere; there have been some supplements (especially Dragon magazine articles) that try to offer more "utilitarian, everyday" spells. For instance, I fully expect Eberron adepts and magewrights would be capable of such a spell.

[Mayhem]

For those in new zealand, a gold piece appears to be about the size of a 10cent piece. Very strange. For australians, it seems a gold piece would correspond to a 5 cent piece.
My calculations are only rough though, the average isotope mass of gold was about 3 times that of copper and nickel so that's what I did.

[Sacrieur]

They're probably not made out of pure gold, they're probably mixed with something else to make them more durable. Since this material is likely more light than gold, the coin will be bigger.

[Tetsubo 57]

Who uses mithral as a currency? I've never run accross mithral pieces, maybe that's why.

I have used mithril coins in the past for Dwarven cultures.

[Firechanter]

@Mayhem: isotope mass is irrelevant. You need to use the densities. Copper and Nickel both roughly have 9g/cm³, whereas gold has 19g/cm³, so the factor is roughly 2 and not 3.